Non-conventional vasopressors in septic shock: effects on hepatosplanchnic blood flow.

Vasopressors are necessary to treat the vasodilation characteristic of hypotension in septic shock. In addition to noradrenaline, the reference vasopressor, various drugs, including dopamine, adrenalin, phenylephrine, L-NMMA (a nitric oxide synthase inhibitor), and vasopressin have been used in clinical septic shock. The available clinically relevant data on the effects of "non-conventional" vasopressors on splanchnic circulation is very limited or nonexistent, and their safety has not been demonstrated. All these drugs can modify the perfusion and metabolism of splanchnic organs, changes which cannot be predicted from changes in systemic circulation or metabolism. Due to the complexity of actions and the high potential for severe adverse effects, "compassionate" use of unconventional vasopressors to treat hypotension in septic shock should be abandoned outside the scope of controlled clinical trials.